Mancini maintains the dismissal was harsh but conceded, as he met the media early on Monday to preview the Stoke game, an appeal may not succeed.

Appealing would have allowed Nasri to face Stoke as, due to the holiday season, a hearing would not have been heard until Wednesday.

But by doing so the club would run the risk of having the ban extended if the appeal was deemed frivolous.

With Yaya Toure, Kolo Toure and Abdul Razak now due to depart for African Nations Cup duty with Ivory Coast after the Stoke game - rather than after Saturday's FA Cup tie against Watford as first thought - it was considered too much of a gamble.

Mancini said: "We don't know what can happen if we appeal. Usually they reject an appeal.

"This could be a problem because after this game we lose three players - Yaya, Kolo, Razak and we don't want to lose another."

With injuries also affecting the squad, Mancini has admitted he may have to bring in new faces in the January transfer window.

When asked if that was a possibility, the Italian said: "Probably - we can have a problem because we lose three players and we have Micah (Richards), I don't think he can play until the end of February.

"Jack (Rodwell) - we don't know when he can play. Maybe we can recover (Aleksandar) Kolarov in two weeks. We will see this in the next days."

Right-back Richards has been out with a knee injury since October, while midfielder Rodwell was expected to be out until early in the new year with a hamstring problem.

Defender Maicon has also been receiving treatment for a knee injury in Italy and striker Mario Balotelli is not expected to return from a virus until the Watford game.

It had been widely assumed Mancini might have to move out players in order to recruit but he insists he has no intention of selling.

He said: "We can't sell players. We don't have enough players to play if we sell players."

Balotelli, fellow forward Edin Dzeko and defenders Kolo Toure and Joleon Lescott are among those who have been linked with moves.

Dzeko staked his claim for a regular starting place with the opening two goals at Norwich. The Bosnian claimed a hat-trick but his third 'goal' was recorded as an own goal against goalkeeper Mark Bunn.

Mancini said: "We need to change the rules because there are in our team 23 players that want to start the game. This is impossible.

"It is important that like Edin, when they have a chance to play, they should take their chance.

"If he scores three goals every game we don't have a problem.

"I am happy for Edin because I think he deserves to score. He scored three goals but he did also a good performance. I hope he can continue to score and play well, like Sergio (Aguero) and Carlos (Tevez)."

After their magnificent 2012, during which they won a first league title for 44 years, City will begin the new year trailing Manchester United by seven points at the top of the table.

Mancini knows Stoke, unbeaten in their last 10 games, will be tough opponents to start 2013.

He said: "Not only now - it always is very difficult to beat Stoke because they are strong, they are tall, they fight on every ball.